Knowledge Base / Protocols / DeviceNet

1799wr-DASCII Frequently Asked Questions

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1.    1.     Where is the 1799wr-DASCII gateway User’s Manual located?

The User’s Manual is available from our web site Support -> Technical Data

2.    2.     What is a 1799wr-DASCII gateway and why should I consider purchasing one for my DeviceNet network?

The 1799wr-DASCII gateway is a communications adapter device that provides you with a flexible DeviceNet interface to a wide variety of ASCII devices. It allows you to easily and conveniently connect and integrate peripheral products with RS-232, RS-422 or RS-485 serial ports into a DeviceNet system enabling you to select just the right peripheral devices for your application without limiting your selection to DeviceNet-cable devices only.


3.   How can I change the DeviceNet MAC ID of my 1799wr-DASCII?

The address of the 1799wr-DASCII will come preset from the factory for address 63. You may change the address using the two rotary switches on the unit: they can be set to any address from 0 to 63 for DeviceNet. The most significant digit should be set with the MSB switch and the least significant digit, likewise, should be set with the LSB switch. If the switches are set to any number from 64 to 99, it will read the switch setting from software, which could be the last known switch setting.  When a new switch setting and MAC ID are desired, first remove power, then change switches to new settings, then reapply power.  The address of the device will not change if the switches are moved while the device is powered. However, the DeviceNet module LED will flash Red indicating that the address has been changed since the last power up.


4.   What electrical connections are required for a 1799wr-DASCII gateway?

DeviceNet Cable Connection:

1, 5-pin pluggable header (male, Phoenix Contact MSTBA 2.5/5-G-5.08/AU or equivalent)


Serial Cable Connections: RS-232, RS-422 or RS-485

1, DB9 port (male, 9-pin D-sub)


5.       How do I begin to use a 1799wr-DASCII gateway?

You can begin to use a 1799wr-DASCII gateway by following the User’s Manual Quick Start instructions.


6.   What are the LEDs on the 1799wr-DASCII indicating?

There are two sets of LEDs on the unit. Green LEDs are used as indicators for the serial communication receive (RX) and transmit (TX). The two bi-color LEDs are used to indicate the DeviceNet module (MOD) and network (NET) status. For troubleshooting or further information on status definitions corresponding to LED actions see LED Operation in the 1799wr-DASCII User’s Manual.     



7.       How do I physically mount the 1799wr-DASCII gateway?

You can panel mount the 1799wr-DASCII with 4 screws or bolts. See the User’s Manual for locations and dimensions.


8.       What are some common applications for the 1799wr-DASCII gateway?

A 1799wr-DASCII gateway provides DeviceNet communications for weigh scales, bar code readers and scanners, display panels, robots, drives, operator stations / HMI, magnetic code readers and other ASCII serial devices.


9.       Is the 1799wr-DASCII gateway designed to plug-n-play?

Yes, the 1799wr-DASCII gateway is designed to plug-n-play using our factory default settings: serial framing of 7N2, serial baud rate of 9600, max number of receive and transmit characters set to 20, pad mode ON, etc. The full list of default settings can be found under Default Settings in the User’s Manual.

If you wish to change any parameters from their default settings you will need to use a DeviceNet software configuration tool. Many of these tools have EDS readers, which make the editing process easier.



10.   Does a 1799wr-DASCII gateway provide electrical isolation?

Yes, the 1799wr-DASCII gateway provides 50V (continuous), basic insulation type electrical isolation.


11.   What are the currently available 1799wr-DASCII gateway models?

There is currently one 1799wr-DASCII model available.


12.   On what DeviceNet baud rates does the 1799wr-DASCII communicate?

The unit works with 125k, 250k or 500k baud rates. It is default set to autobaud on DeviceNet. A fixed baud rate of 125k, 250k or 500k may also be assigned with a software configuration tool.


13.   On what baud rates does the 1799wr-DASCII serial port communicate?

The serial port on the 1799wr-DASCII will communicate on baud rates of: 1200, 2400, 4800, 9600, 19.2k, 38.4k, 57.6k, or 115.2k baud.



14.   How do I connect a 1799wr-DASCII gateway to a serial port device?

You connect to a serial port device with the serial DB9 connector using a 3-wire (or 5-wire for hardware handshaking) communication cable.  Note:  All pins are active, do not use a standard cross over cable.  The serial DB9 connectors on the unit have signal/pin assignments as follows:


Pin #





no connection





no connection

no connection



no connection

no connection


no connection


no connection






no connection


no connection










no connection





15.   How is the Master Handshake mode different from the Hardware handshake RTS/CTS?

Master Handshake mode is a data control mechanism between the DeviceNet master and the 1799wr-DASCII (after the DASCII receives data from serial device), communicated in IO message. The 1799wr-DASCII indicates new data arrival and waits for Master to issue a new record number, to be used with new data. The hardware handshaking via RTS/CTS requires two additional signal lines on the serial side and it controls the data before it is received.




16.   When should I turn Pad Mode OFF? Or what configuration parameter should I check when the scanner cannot stay connected to the 1799wr-DASCII due to an IO size error?

If the DeviceNet scanner or the master device needs to be pre-configured with an input (produce) size before making a connection, or if the serial device will be sending variable data size strings, you will need to leave the PAD Mode ON (default setting). This parameter should be checked if the 1799wr-DASCII will not stay connected due to an IO size error.


17.   What should my master device logic be doing to see if new data is present in a poll message?

The Master program logic should be looking at the Receive Record Number and comparing it with the last stored record number to monitor new data arrival in Immediate (Non-Handshake) Mode. In the Master Handshake mode, the program should be looking at the New Data bit in status and if detected, should supply the new record number and wait for the 1799wr-DASCII to produce data along with that record number.


18.   What does the 1799wr-DASCII require for power?

The 1799wr-DASCII receives all necessary power from the DeviceNet network cable. This should be between 11 and 25 Vdc. It consumes 0.5 watts of power maximum.


19.   Where should I use a 1799wr-DASCII vs. a 1782-JDCx gateway?

The 1799wr-DASCII has a form factor designed for panel mounting and the 1782-JDCx is designed for DIN rail mounting.  The 1782-JDCx models are functionally very similar to the 1799wr-DASCII.  The additional parameters of the 1782-JDCE-1 are most similar to the 1799wr-DASCII and offer some additional flexibility.  Also the 1799wr-DASCII is designed for RS232/422/485 serial communication, whereas the 1782-JDCx models are designed for a specific serial communication type.


20.   How do I access the serial ASCII data from a 1799wr-DASCII gateway?

When configuring your PLC, you have the option to memory map the ASCII data from the 1799wr-DASCII to a location on your PC. The ASCII data can be found at this location.


21.   When do I need to use an EDS (electronic data sheet) file for a 1799wr-DASCII gateway?

An EDS file is not necessary, but it makes configuring the 1799wr-DASCII (changing baud rate, framing, etc.) far easier than if you were to try to change the device parameters by editing the attributes of certain class objects and instances without the aid of a configuration tool. There are many software configuration tools available with EDS readers that can be used to set up the device.


22.   What is the proper cable to use for a 1799wr-DASCII gateway serial connection?

The proper cable selection depends upon the serial communication baud rate desired and the total cable length.  Use 3-wire or 5-wire shielded cable with DB9 end connectors compatible with the 1799wr-DASCII and your serial device.


23.   Where can I purchase the proper cable for a 1799wr-DASCII gateway serial connection?

You can purchase the proper cable from many suppliers, fitted with the connectors required for the gateway and serial device being used.